The Mountain Drive is a unique gearing system that is built-in inside of the crankset that reduces all gears by a factor of 2.5. In high gear one revolution of the crank results in one revolution of the chainring. In low gear 2.5 turns of the crank result in one revolution of the chainring.

The complete system fits in most standard bottom bracket shells. Installation is quick and easy. The complete weight with the axle, bearings, spider, and cranks is 890 gr. The unit is sealed to keep out dirt and water.

The Speed Drive is a road version of the system that in low gear will turn the chainrings 1.65 times for each revolution of the cranks.

It's so easy: push with the heel of your shoe either on the right or on the left side of the axle on the push button to change from high to low gear or vice versa.